The present invention relates to an optical disk apparatus for recording predetermined user data on an optical disk having a concentric or spiral track and, more particularly, to an optical disk apparatus for simultaneously recording user data and an error correction code (ECC) for correcting an error of the user data.
A rewritable optical disk and an optical disk apparatus for recording user data on such an optical disk have recently appeared. The optical disk has a concentric or spiral track, and a plurality of sector regions each having a predetermined track length are formatted in the track. A predetermined number of sector regions constitute an ECC block.
User data and error correction codes are recorded in the sector regions. What is noted is that the user data and error correction codes recorded in the same sector region do not possess a complete one-to-one correspondence to each other. The error correction codes are recorded at once for the user data recorded in all the sector regions constituting an ECC block. In other words, when user data in one of the sector regions constituting an ECC block is rewritten, error correction codes within all the sector regions constituting the ECC block must to be rewritten accordingly.
Consequently, in the optical disk apparatus, data is recorded or rewritten on the optical disk in units of ECC block. For example, when predetermined user data is recorded in a specific sector, data of the entire ECC block including the specific sector is read out of the optical disk by the optical disk apparatus. The predetermined user data is recorded in the specific sector of the ECC block, and a new ECC block is generated. Data of the newly-generated ECC block is recorded on the optical disk.
The foregoing optical disk apparatus has the problem that when data is recorded in an arbitrary sector region of a plurality of sector regions constituting an ECC block, data within all of sector regions has to be rewritten. This decreases the data recording speed, deteriorates the recording film of the optical disk, and lowers the reliability of data.